The SNO+ Collaboration reports the first evidence of reactor antineutrinos in a Cherenkov detector. The nearest nuclear reactors are located 240 km away in Ontario, Canada. This analysis uses events ...with energies lower than in any previous analysis with a large water Cherenkov detector. Two analytical methods are used to distinguish reactor antineutrinos from background events in 190 days of data and yield consistent evidence for antineutrinos with a combined significance of 3.5σ.
The SNO+ collaboration reports its first spectral analysis of long-baseline
reactor antineutrino oscillation using 114 tonne-years of data. Fitting the
neutrino oscillation probability to the ...observed energy spectrum yields
constraints on the neutrino mass-squared difference $\Delta m^2_{21}$. In the
ranges allowed by previous measurements, the best-fit $\Delta m^2_{21}$ is
(8.85$^{+1.10}_{-1.33}$) $\times$ 10$^{-5}$ eV$^2$. This measurement is
continuing in the next phases of SNO+ and is expected to surpass the present
global precision on $\Delta m^2_{21}$ with about three years of data.
The direction of individual \(^8\)B solar neutrinos has been reconstructed using the SNO+ liquid scintillator detector. Prompt, directional Cherenkov light was separated from the slower, isotropic ...scintillation light using time information, and a maximum likelihood method was used to reconstruct the direction of individual scattered electrons. A clear directional signal was observed, correlated with the solar angle. The observation was aided by a period of low primary fluor concentration that resulted in a slower scintillator decay time. This is the first time that event-by-event direction reconstruction in high light-yield liquid scintillator has been demonstrated in a large-scale detector.
The SNO+ Collaboration reports the first evidence of reactor antineutrinos in a Cherenkov detector. The nearest nuclear reactors are located 240~km away in Ontario, Canada. This analysis uses events ...with energies lower than in any previous analysis with a large water Cherenkov detector. Two analytical methods are used to distinguish reactor antineutrinos from background events in 190 days of data and yield consistent evidence for antineutrinos with a combined significance of 3.5\(\sigma\).
This paper reports results from a search for single and multi-nucleon disappearance from the \(^{16}\)O nucleus in water within the \snoplus{} detector using all of the available data. These ...so-called "invisible" decays do not directly deposit energy within the detector but are instead detected through their subsequent nuclear de-excitation and gamma-ray emission. New limits are given for the partial lifetimes: \(\tau(n\rightarrow inv) > 9.0\times10^{29}\) years, \(\tau(p\rightarrow inv) > 9.6\times10^{29}\) years, \(\tau(nn\rightarrow inv) > 1.5\times10^{28}\) years, \(\tau(np\rightarrow inv) > 6.0\times10^{28}\) years, and \(\tau(pp\rightarrow inv) > 1.1\times10^{29}\) years at 90\% Bayesian credibility level (with a prior uniform in rate). All but the (\(nn\rightarrow inv\)) results improve on existing limits by a factor of about 3.
Recently, we have discussed des Cloizeaux's law to study the loop correlations shown by a network of Abelian strings at formation. Here we report on non-Abelian strings and compare them with the ...Abelian ones. We confirm the results for the Abelian case but we also show that a direct fit of the general analytical prediction previously reported on the exponent of the two-point correlation function between loop formation sites is much better than the one given for the Abelian configurations. We argue that it is due to the higher concentration of the network.
We describe the configurational critical behavior of a statistical ensemble of strings on a lattice with periodic boundary conditions by a model of polymers at intermediate concentrations. The ...concentration concept is introduced and its configurational phase diagram'' is presented for different scaling regions. We analyze des Cloizeaux's law for strings to gain insight into the intrinsic nature of correlations. By only using power laws without any free parameter of dynamical theories, we find the exact prediction {gamma}=5/3 for the power-law exponent of a two-point correlation function of (cosmic-) string formation sites in terms of des Cloizeaux's law for dense polymers. A detailed numerical analysis by Monte Carlo simulation is reported.
Scaling in a string network ALLEGA, A. M
Physical review. D, Particles and fields,
08/1989, Letnik:
40, Številka:
4
Journal Article
We study statistical properties of U(1) strings at formation on the torus. Two topological classes are distinguished: strings with trivial topology and strings with any possible nontrivial topology. ...A new scaling phase at the very-long-string limit is found. Short-range correlations for the new phase are reported in the trivial sector. We analyze the mean length for the two classes and the infinite-volume limit is considered in detail. The intersection probability is used for a consistency check of the simulation.
A complete scaling picture for a network of Abelian strings on a torus has been presented in a previous paper. Kibble has given a nice model to study SO(3) strings on the lattice. In the present ...work, non-Abelian strings are realized by Kibble's criterion and a scaling picture comes out very similar to that of my previous paper but a third phase is distinguished by a new characteristic length. Topological contributions are discussed with respect to nontrivial ones. Two general classes of topology are selected and the infinite-volume limit is analyzed.
